Variable displacement vane pump

ABSTRACT

A vane pump includes: a rotor connected to a driving shaft; a plurality of vanes provided so as to be capable of reciprocating in a radial direction with respect to the rotor; a cam ring having a cam face on which a tip-ends of the vanes slide with the rotation of the rotor, the cam ring being provided so as to be capable of being made eccentric with respect to the rotor; a second pump body configured to accommodate the cam ring; and a spring interposed between the cam ring and the second pump body in a compressed state, the spring being configured to bias the cam ring in the direction in which the amount of eccentricity with respect to the rotor is increased. The cam ring and the second pump body have seating surfaces on which the spring is seated and grooves formed in the seating surfaces.

TECHNICAL FIELD

The present invention relates to a variable displacement vane pump.

BACKGROUND ART

JP2013-057326A discloses a variable displacement vane pump that comprises: a housing consisting of a pump body having a U-shaped cross-section that has a pump accommodating chamber and a cover member that closes an opening of the pump body on one end; pump elements consisting of a rotor and vanes, the rotor being freely rotatably accommodated in the pump accommodating chamber and is connected to a driving shaft at its center portion, and the vanes being respectively received in a plurality of slits that are formed by being cut in a radiating pattern in an outer circumference portion of the rotor, such that the vanes are capable of moving into and out from the slits; a cam ring that is arranged on the outer circumferential side of the pump elements so as to be able to be decentered with respect to the rotation center of the rotor, the cam ring being arranged to define, with the rotor and adjacent vanes, a plurality of pump chambers serving as working oil chambers; and a spring serving as a biasing member that is received in the pump body so as to always bias the cam ring in the direction in which an amount of eccentricity of the cam ring with respect to the rotation center of the rotor is increased.

In addition, JP2013-057326A discloses that the cam ring has: a pivot portion that is projectingly provided at a predetermined position of the outer circumference portion so as to form the eccentrical swing fulcrum; and an arm portion that is projectingly provided at a position on the other side from the pivot portion with respect to the center of the cam ring so as to be linked to the spring.

SUMMARY OF INVENTION

With the variable displacement vane pump disclosed in JP2013-057326A, the biasing member (the spring) is installed in a compressed state between the cam ring and an accommodating member (the pump body) accommodating the cam ring. Thus, when such a vane pump is to be assembled, the biasing member for biasing the cam ring needs to be installed in the accommodating member accommodating the cam ring while keeping the biasing member compressed.

It is conceivable to use a jig for compressing the biasing member in an installation work for installing the biasing member in the accommodating member. However, even if the biasing member is installed in the accommodating member in a compressed state by using the jig, because a biasing force from the biasing member is exerted to the jig, it is difficult to withdraw the jig from between the biasing member and the seating surface. As described above, the installation work of the biasing member is troublesome, and there is a need to perform the installation work more easily.

An object of the present invention is to improve assemblability of a variable displacement vane pump.

According to one aspect of the present invention, a variable displacement vane pump includes: a rotor connected to a driving shaft; a plurality of vanes provided so as to be capable of reciprocating in a radial direction with respect to the rotor; a cam ring having an inner circumferential surface on which tip-ends of the vanes slide with rotation of the rotor, the cam ring being provided so as to be made eccentric with respect to the rotor; an accommodating member configured to accommodate the cam ring; and a biasing member interposed between the cam ring and the accommodating member in a compressed state, the biasing member being configured to bias the cam ring in a direction in which an amount of eccentricity with respect to the rotor is increased; wherein at least one of the cam ring and the accommodating member has a seating surface on which the biasing member is seated and a groove formed in the seating surface.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of a variable displacement vane pump according to a first embodiment of the present invention, and is a diagram showing a state in which the pump cover is removed.

FIG. 2 is a sectional view of the variable displacement vane pump according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining a method for installing the biasing member of the variable displacement vane pump according to the first embodiment of the present invention, and is a diagram showing a state before the biasing member is installed.

FIG. 4 is a diagram for explaining the method for installing the biasing member of the variable displacement vane pump according to the first embodiment of the present invention, and is an enlarged diagram showing a state in which the biasing member is accommodated in an accommodating member.

FIG. 5 is a diagram for explaining the method for installing the biasing member of the variable displacement vane pump according to the first embodiment of the present invention, and is an enlarged diagram showing a state in which the biasing member is seated.

FIG. 6 is an enlarged diagram showing a first modification of the variable displacement vane pump according to the first embodiment of the present invention.

FIG. 7 is an enlarged diagram showing a second modification of the variable displacement vane pump according to the first embodiment of the present invention.

FIG. 8 is a plan view of the variable displacement vane pump according to a second embodiment of the present invention, and is a diagram showing a state in which the pump cover is removed.

FIG. 9 is a diagram for explaining the method for installing the biasing member of the variable displacement vane pump according to the second embodiment of the present invention, and is an enlarged diagram showing a state in which the biasing member is accommodated in the accommodating member.

FIG. 10 is a diagram for explaining the method for installing the biasing member of the variable displacement vane pump according to the second embodiment of the present invention, and is an enlarged diagram showing a state in which a cam ring is accommodated in the accommodating member.

FIG. 11 is a diagram for explaining the method for installing the biasing member of the variable displacement vane pump according to the second embodiment of the present invention, and is an enlarged diagram showing a state in which the biasing member is seated.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described below with reference to the attached drawings.

First Embodiment

An overall configuration of a variable displacement vane pump (hereinafter, simply referred to as “vane pump”) 100 according to a first embodiment of the present invention will be described first with reference to FIGS. 1 and 2.

The vane pump 100 is used as a fluid pressure source for a fluid pressure apparatus mounted on a vehicle, such as, for example, a continuously variable transmission, etc.

In the vane pump 100, a motive force from an engine (not shown) is transmitted to an end portion of a driving shaft 1, and a rotor 2 linked to the driving shaft 1 is rotated, thereby sucking and discharging working oil serving as working fluid. The rotor 2 is rotated in the anti-clockwise direction as shown by an arrow in FIG. 1.

As shown in FIGS. 1 and 2, the vane pump 100 is provided with: a plurality of vanes 3 that are provided so as to be capable of reciprocating in the radial direction with respect to the rotor 2; a cam ring 4 that accommodates the rotor 2 and has a cam face 4 a that is an inner circumferential surface thereof on which tip-ends of the vanes 3 slide by rotation of the rotor 2, the cam ring 4 being provided so as to be made eccentric with respect to the center of the rotor 2; a first pump body 10 into which the driving shaft 1 is inserted; a second pump body 20 that serves as an accommodating member for accommodating the cam ring 4; and a pump cover 15 that is provided so as to sandwich the second pump body 20 with the first pump body 10 so as to close an opening of the second pump body 20. As shown in FIG. 2, the driving shaft 1 is rotatably supported by the first pump body 10.

As shown in FIG. 1, in the rotor 2, slits 7 respectively having openings in an outer circumferential surface are formed in a radiating pattern with a predetermined gaps. The vanes 3 are respectively inserted into the slits 7 so as to be freely reciprocatable. In the slits 7, back pressure chambers 8 into which discharge pressure is guided are defined by base-end portions of the vanes 3.

The vanes 3 are pushed in the directions in which the vanes 3 are drawn out from the slits 7 by the pressure of the working oil guided into the back pressure chambers 8, and the tip-end portions of the vanes 3 are brought into contact with the cam face 4 a of the cam ring 4. With such a configuration, a plurality of pump chambers 9 are defined in the cam ring 4 by the outer circumferential surface of the rotor 2, the cam face 4 a of the cam ring 4, and the adjacent vanes 3.

The cam ring 4 has a substantially annular main body portion 5 having the cam face 4 a that is the inner circumferential surface on which the tip-ends of the vanes 3 slide, and a lever portion 6 that is formed by extending in the radial direction from the main body portion 5. A proximal end of the lever portion 6 is connected to the main body portion 5, and a distal end of the lever portion 6 is formed with a substantially flat seating surface 6 a on which a spring 30, which will be described later, is seated.

In addition, the cam ring 4 has a suction region in which volumes of the pump chambers 9, which are defined between respective vanes 3 that slide on the cam face 4 a by the rotation of the rotor 2, are increased and a discharge region in which volumes of the pump chambers 9 are decreased. As described above, respective pump chambers 9 are expanded/contracted by the rotation of the rotor 2.

As shown in FIG. 2, in the first pump body 10, an accommodating concave portion 10 a is formed at a position facing the rotor 2 and the cam ring 4. In the accommodating concave portion 10 a, a side plate 11 is arranged so as to come into contact with one-side surfaces (right-side surfaces in FIG. 2) of the rotor 2 and the cam ring 4. The side plate 11 is formed so as to form a surface substantially flush with an end surface of the first pump body 10 facing the second pump body 20. On the other-side surfaces (left-side surfaces in FIG. 1) of the rotor 2 and the cam ring 4, the pump cover 15 is arranged so as to come into contact therewith. The side plate 11 and the pump cover 15 are arranged in a state in which both side surfaces of the rotor 2 and the cam ring 4 are sandwiched, and thereby, the pump chambers 9 are sealed. In this embodiment, although the pump cover 15 is brought into contact with the other-side surfaces of the rotor 2 and the cam ring 4 to seal the pump chambers 9, a side plate may be provided on the pump cover 15 so as to be brought into contact with the other-side surfaces of the rotor 2 and the cam ring 4, and the pump chambers 9 may be sealed with the side plate.

The pump cover 15 is formed with a suction port 16 that has an arc-shaped opening in a manner corresponding to the suction region of the pump chambers 9 and a suction passage 17 that is in communication with a tank (not shown) and that guides the working oil in the tank to the pump chambers 9 through the suction port 16. In addition, the side plate 11 is formed with a discharge port 12 so as to penetrate therethrough. The discharge port 12 has an arc-shaped opening in a manner corresponding to the discharge region of the pump chambers 9.

The first pump body 10 is formed with a high-pressure chamber 13 to which the working oil that has been discharged from the pump chambers 9 in the discharge region is guided. The working oil discharged from the pump chambers 9 is guided to the high-pressure chamber 13 through the discharge port 12 formed in the side plate 11. The working oil that has been guided to the high-pressure chamber 13 is supplied to an external hydraulic apparatus through a discharge passage (not shown) that is formed in the first pump body 10 and is in communication with the high-pressure chamber 13.

In the vane pump 100, as the rotor 2 is rotated, the working oil is sucked from the tank to each of the pump chambers 9 in the suction region of the cam ring 4 through the suction port 16 and the suction passage 17, and the working oil is discharged to the outside from each of the pump chambers 9 in the discharge region of the cam ring 4 through the discharge port 12 and the discharge passage. As described above, in the vane pump 100, the working oil is supplied/discharged by expansion/contraction of the respective pump chambers 9 caused by the rotation of the rotor 2.

The second pump body 20 serves as the accommodating member that accommodates the cam ring 4, and at the same time, the second pump body 20 also functions as an adapter ring that supports the cam ring 4 in a freely swingable manner. As shown in FIG. 1, the inner circumferential surface of the second pump body 20 is provided with a support pin 21 that supports the cam ring 4. The cam ring 4 swings about the support pin 21 in the second pump body 20 and is made eccentric with respect to the center of the rotor 2. As described above, the support pin 21 serves as the swing fulcrum of the cam ring 4.

On the inner circumferential surface of the second pump body 20, a first restriction portion 22 and a second restriction portion 23 are respectively formed so as to bulge out from the inner circumferential surface. The first restriction portion 22 restricts movement of the cam ring 4 in the direction in which an amount of eccentricity with respect to the rotor 2 is decreased, and the second restriction portion 23 restricts movement of the cam ring 4 in the direction in which the amount of eccentricity with respect to the rotor 2 is increased. In other words, the first restriction portion 22 defines the minimum amount of eccentricity of the cam ring 4 with respect to the rotor 2, and the second restriction portion 23 defines the maximum amount of eccentricity of the cam ring 4 with respect to the rotor 2.

At a position axisymmetric to the support pin 21 in the inner circumferential surface of the second pump body 20, a seal member 24 is fitted so as to be in sliding contact with an outer circumferential surface of the main body portion 5 of the cam ring 4 when the cam ring 4 swings around.

As described above, in an outer circumference accommodating space on the outer side of the cam ring 4 formed between the outer circumferential surface of the cam ring 4 and the inner circumferential surface of the second pump body 20, a first fluid pressure chamber 25 and a second fluid pressure chamber 26 are defined by the support pin 21 and the seal member 24. The configuration is not limited thereto, and an adapter ring may be provided in addition to the second pump body 20, and the first fluid pressure chamber 25 and the second fluid pressure chamber 26 may be defined between the outer circumferential surface of the cam ring 4 and an inner circumferential surface of the adapter ring.

The second pump body 20 is formed with a spring chamber 27 in which the coil spring (hereinafter, simply referred to as “spring”) 30 serving as a biasing member is accommodated. The spring chamber 27 is in communication with the first fluid pressure chamber 25. In addition, the distal end of the lever portion 6 is accommodated in the spring chamber 27. The spring 30 serving as the biasing member is interposed between the lever portion 6 of the cam ring 4 and the second pump body 20 in a compressed state. Specifically, one end (a lower end in FIG. 1) of the spring 30 is seated on a seating surface 20 a that is a wall surface defining the spring chamber 27 in the second pump body 20, and other end (an upper end in FIG. 1) of the spring 30 is seated on the seating surface 6 a formed in the distal end of the lever portion 6. The spring 30 biases the lever portion 6 of the cam ring 4 in the direction in which the amount of eccentricity of the cam ring 4 with respect to the rotor 2 is increased.

The first fluid pressure chamber 25 is in communication with the suction passage 17 that sucks the working oil from the tank (see FIG. 2). A discharge pressure of the pump chambers 9, the pressure level of which is controlled by a control valve (not shown), is guided to the second fluid pressure chamber 26. Because the pressure of the working oil guided to the second fluid pressure chamber 26 is higher than the pressure in the suction passage 17, the cam ring 4 is subjected to a thrust in the direction in which the amount of eccentricity with respect to the rotor 2 is reduced due to the pressure difference. Thus, the cam ring 4 undergoes swinging movement about the support pin 21 such that the thrust caused by the pressure difference between the first fluid pressure chamber 25 and the second fluid pressure chamber 26 is balanced with the biasing force exerted by the spring 30. With the swinging movement of the cam ring 4 about the support pin 21, the amount of eccentricity of the cam ring 4 with respect to the rotor 2 is changed to change the discharge capacity of the pump chambers 9.

When the thrust caused by the pressure difference between the first fluid pressure chamber 25 and the second fluid pressure chamber 26 is larger than the biasing force exerted by the spring 30, the amount of eccentricity of the cam ring 4 with respect to the rotor 2 is reduced, causing the discharge capacities of the pump chambers 9 to be reduced. In contrast, the thrust caused by the pressure difference between the first fluid pressure chamber 25 and the second fluid pressure chamber 26 is smaller than the biasing force exerted by the spring 30, the amount of eccentricity of the cam ring 4 with respect to the rotor 2 is increased, causing the discharge capacities of the pump chambers 9 to be increased. As described above, in the vane pump 100, depending on the pressure difference between the first fluid pressure chamber 25 and the second fluid pressure chamber 26 and the biasing force exerted by the spring 30, the amount of eccentricity of the cam ring 4 with respect to the rotor 2 is changed to change the discharge capacities of the pump chambers 9.

As shown in FIG. 1, grooves 6 b and 20 b are respectively formed at positions facing the spring 30 in the seating surface 6 a for the spring 30 of the lever portion 6 of the cam ring 4 and the seating surface 20 a for the spring 30 of the second pump body 20. The groove 6 b formed in the lever portion 6 is formed along the center axis direction of the rotor 2 (the direction perpendicular to the plane of the paper in FIG. 1), and the groove 6 b has an opening in an end surface of the lever portion 6 on the pump cover 15 side (the end surface facing the pump cover 15). In addition, the groove 20 b formed in the second pump body 20 is formed along the center axis direction of the rotor 2, and the groove 20 b has an opening in an end surface of the second pump body 20 on the pump cover 15 side. The position facing the spring 30 means the position where the grooves 6 b and 20 b respectively oppose to the parts of the spring 30.

Next, a method for producing the vane pump 100 will be described with reference to FIGS. 3 to 5. In the following, a method for installing the spring 30 in the second pump body 20 will be mainly described.

In a state before the spring 30 is installed in the second pump body 20, the second pump body 20 is mounted in the first pump body 10, and as shown in FIG. 3, the rotor 2, the vanes 3, and the cam ring 4 are installed in the second pump body 20.

In this state, as shown in FIG. 4, the spring 30 is clamped and compressed in the axial direction by a jig T capable of clamping the spring 30 in the axial direction, and the compressed spring 30 is accommodated between the lever portion 6 of the cam ring 4 and the second pump body 20. As shown in FIG. 4, the jig T is provided with, for example, a pair of clamping parts having a circular cross-section, and the jig T is configured such that the distance between the clamping parts is increased/decreased by an external force. In other words, the jig T is configured such that the respective clamping parts come close to/away from each other by the external force.

Next, from the state in which the spring 30 is compressed by the jig T, a clamping (compressing) force of the jig T for the spring 30 is gradually reduced, thereby allowing the spring 30 to extend. Subsequently, both end portions of the spring 30 are respectively seated on the seating surface 20 a of the second pump body 20 and the seating surface 6 a of the lever portion 6 of the cam ring 4. At this time, as shown in FIG. 5, the clamping parts of the jig T are respectively inserted into the groove 6 b of the lever portion 6 and the groove 20 b of the second pump body 20. As described above, the grooves 6 b and 20 b formed in the respective eating surfaces 6 a and 20 a of the lever portion 6 and the second pump body 20 serve as jig insertion grooves into which the jig T for compressing the spring 30 is inserted.

Next, the jig T is withdrawn from the grooves 6 b and 20 b in the seating surfaces 6 a and 20 a of the lever portion 6 and the second pump body 20. In this configuration, the depths of the grooves 6 b and 20 b are respectively formed so as to be greater than the thickness (outer diameter) of the jig T along the axis of the spring 30. Therefore, as shown in FIG. 5, in a state in which the clamping parts of the jig T are inserted in the grooves 6 b and 20 b, gaps are respectively formed between the clamping parts of the jig T and the grooves 6 b and 20 b. Because the clamping parts of the jig T are inserted in the grooves 6 b and 20 b, the clamping parts are prevented from being caught between the spring 30 and the lever portion 6 and/or between the spring 30 and the second pump body 20. Therefore, both end portions of the spring 30 are respectively seated on the seating surfaces 6 a and 20 a with high reliability. In addition, because the biasing force exerted by the spring 30 is received by the seating surfaces 6 a and 20 a of the lever portion 6 and the second pump body 20 and the biasing force is not exerted to the jig T, the jig T can be withdrawn from the grooves 6 b and 20 b with ease. Thus, the spring 30 can be installed between the second pump body 20 and the lever portion 6 with ease, and so, it is possible to improve the assemblability of the vane pump 100.

Next, a modification of the first embodiment will be described.

In the above-described first embodiment, the first pump body 10 that rotatably supports the driving shaft 1 and the second pump body 20 that serves as the accommodating member for accommodating the cam ring 4 are formed separately. In contrast, the first pump body 10 and the second pump body 20 may be formed integrally.

In addition, in the above-described first embodiment, a single groove is formed in each of the seating surface 6 a of the lever portion 6 and the seating surface 20 a of the second pump body 20. In contrast, the number and shapes of the grooves 6 b and 20 b may be set arbitrary in accordance with the shape of the jig T. For example, a plurality of (two or more) grooves may be provided in each of the seating surfaces 6 a and 20 a. In addition, the grooves 6 b and 20 b may be formed in the seating surfaces 6 a and 20 a so as to have a size capable of receiving two or more jigs T.

In addition, in the above-described first embodiment, the grooves 6 b and 20 b are respectively formed in both of the seating surface 6 a of the lever portion 6 and the seating surface 20 a of the second pump body 20. In contrast, the groove may be formed only in the seating surface 20 a of the second pump body 20. In this case, as shown in FIG. 6, the lever portion 6 is formed so as to define a space for inserting the clamping part of the jig T between the lever portion 6 and the second pump body 20, and the spring 30 is clamped by the jig T together with the lever portion 6 in a state in which the spring 30 is seated on the seating surface 6 a of the lever portion 6. The spring 30 may be placed in the second pump body 20 together with the cam ring 4 while holding this state. Thereafter, the clamping force is reduced such that the clamping part of the jig T on the second pump body 20 side is inserted into the groove 20 b formed in the seating surface 20 a of the second pump body 20, and thereby, the spring 30 is allowed to be seated on the seating surface 20 a of the second pump body 20. With such a configuration, the jig T can be withdrawn with ease, and at the same time, the spring 30 can be installed in the second pump body 20 in a compressed state. In other words, the vane pump 100 may be configured such that, in a state in which the amount of eccentricity of the cam ring 4 is the greatest, i.e. in a state in which an end surface 6 c of the lever portion 6 on the other side of the seating surface 6 a is positioned closest to a wall portion of the second pump body 20, the clamping part of the jig T on the lever portion 6 side does not come into contact with the inner circumferential surface of the second pump body 20, and therefore, the withdrawal of the jig T is not hindered by the second pump body 20.

In addition, as shown in FIG. 7, the groove may be formed only in the seating surface 20 a of the second pump body 20, and a seating member 31 may be provided between the lever portion 6 and the spring 30 separately from the lever portion 6. In this case, the spring 30 and the seating member 31 are inserted into the second pump body 20 by being clamped together by the jig T. In this state, the spring 30 is allowed to extend such that the clamping part of the jig T is inserted into the groove 20 b of the second pump body 20, and thereby, one end of the spring 30 is allowed to be seated on the seating surface 20 a of the second pump body 20 and the seating member 31 is brought into contact with the lever portion 6. A sufficient space is provided between the jig T and the second pump body 20 so that there is no mutual interference. The jig T is engaged with the seating member 31 to clamp the spring 30 with the seating member 31. Therefore, the withdrawal of the jig T is not hindered by the second pump body 20. Thus, the jig T can be withdrawn from the groove 20 b and from between the seating member 31 and the second pump body 20 with ease. Also with such a case, it is possible to achieve a similar effect to that described in the above-mentioned embodiment. Conversely, the groove may be formed only in the seating surface 6 a of the lever portion 6, and at the same time, the seating member 31 may be provided between the spring 30 and the second pump body 20. For the seating member 31, a detailed description will be given in a below-mentioned second embodiment. As described above, as long as at least one of the cam ring 4 or the second pump body 20 has the seating surface (6 a, 20 a) and the groove (6 b 20 b), it is possible to achieve a similar effect to that described in the above-mentioned embodiment.

According to the first embodiment described above, the advantages described below are afforded.

In the vane pump 100, the spring 30 that has been compressed by the jig T in the second pump body 20 is allowed to extend such that the clamping parts of the jig T are inserted in the grooves 6 b and 20 b, and thereby, the spring 30 is allowed to be seated on the seating surfaces 6 a and 20 a. Thereafter, the jig T is withdrawn from the grooves 6 b and 20 b to install the spring 30 in the second pump body 20. As described above, because the grooves 6 b and 20 b are respectively formed in the seating surfaces 6 a and 20 a, the jig T is prevented from being caught between the spring 30 and the seating surfaces 6 a and 20 a, and so, the jig T is not subjected to the biasing force exerted by the spring 30. Thus, the jig T can be withdrawn from the second pump body 20 with ease, and so, it is possible to install the spring 30 in the second pump body 20 with ease. Therefore, the assemblability of the vane pump 100 is improved.

Second Embodiment

Next, the second embodiment of the present invention will be described with reference to FIGS. 8 to 11. In the following, differences from the above-described first embodiment will be mainly described, and components that are the same as those in the vane pump 100 in the above-described first embodiment are assigned the same reference numerals and descriptions thereof will be omitted.

In the above-described first embodiment, the spring 30 is seated on the seating surface 6 a of the lever portion 6 and is seated on the seating surface 20 a of the second pump body 20. In addition, the grooves 6 b and 20 b are respectively formed in the seating surface 6 a of the lever portion 6 and the seating surface 20 a of the second pump body 20. In contrast, in the second embodiment, the seating member 31 is provided between the spring 30 and the lever portion 6 separately from the cam ring 4, and the spring 30 is seated on the seating member 31. In addition, in the second embodiment, the grooves 6 b and 20 b for inserting the clamping parts of the jig T are not formed in the lever portion 6 and the second pump body 20. The configuration of the second embodiment differs from that of the above-described first embodiment with regard to these points.

As shown in FIG. 8, a vane pump 200 according to the second embodiment is further provided with the seating member 31 that is provided between the spring 30 and the lever portion 6 separately from the cam ring 4.

The seating member 31 has a contacting portion 32 that is brought into contact with the lever portion 6 of the cam ring 4 and a disk portion that faces the spring 30.

The disk portion has a seating portion 33 on which the spring 30 is seated and an engagement portion 34 to which the jig T is engaged. The engagement portion 34 is formed by extending radially outwards from the seating portion 33 in an annular shape. The engagement portion 34 forms a gap with the lever portion 6 that is larger than the width (outer diameter) of the jig T. In other words, the thickness of the contacting portion 32 (the length along the axial direction of the spring 30) is set such that the gap that is larger than the width of the jig T is formed between the engagement portion 34 and the lever portion 6.

Next, a method for producing the vane pump 200 will be described. In the following, similarly to the above-described first embodiment, a method for installing the spring 30 will be mainly described.

When the spring 30 is to be installed in the vane pump 200, unlike the above-described first embodiment, the spring 30 and the seating member 31 are installed in the second pump body 20 before the cam ring 4. Thereafter, as shown in FIG. 9, the seating member 31, the spring 30, and an outer wall portion of the second pump body 20 are clamp by the jig T. Specifically, two jigs T provided on one side are engaged with the engagement portion 34 of the seating member 31, and two jigs T provided on the other side are brought into contact with an outer wall surface of the second pump body 20. Thus, the seating member 31, the spring 30, and the second pump body 20 are clamped by the jigs T. With such a configuration, the spring 30 is compressed by the clamping force that is transmitted to the engagement portion 34 of the seating member 31 and the wall portion of the second pump body 20 via the jigs T.

Next, as shown in FIG. 10, while keeping the spring 30 compressed, the cam ring 4 is inserted into the second pump body 20. Thereafter, as shown in FIG. 11, the clamping force exerted by the jigs T is reduced to allow the contacting portion 32 of the seating member 31 to come into contact with the lever portion 6. Then, the jigs T are withdrawn from the second pump body 20. At this time, the jigs T on the one side (on the seating member 31 side) do not come into contact with the lever portion 6 and the inner circumferential surface of the second pump body 20. Thus, the jigs T can be withdrawn with ease, and it is possible to install the spring 30 in the second pump body 20 with easy by withdrawing the jigs T.

As described above, in the second embodiment, by providing the seating member 31, the jigs T can be withdrawn with ease upon installation of the spring 30 even if the grooves 6 b and 20 b are not formed in the lever portion 6 and the second pump body 20.

Next, a modification of the above-described second embodiment will be described.

In the above-described second embodiment, the seating member 31 is provided only between the spring 30 and the lever portion 6. In addition to this configuration, the seating member 31 may be provided between the spring 30 and the second pump body 20. In such a case, although the grooves 6 b and 20 b are not formed in both of the lever portion 6 and the second pump body 20 as described in the above-described second embodiment, it is possible to install the spring 30 in the second pump body 20 by being compressed together with two seating members 31 by the jigs T after the cam ring 4 is accommodated in the second pump body 20 as described in the above-described first embodiment.

In addition, in the above-described second embodiment, the seating member 31 has the seating portion 33 and the engagement portion 34 that are formed integrally as the disk portion. The configuration is not limited thereto, and the seating member 31 may be formed to have an arbitrary shape as long as the seating member 31 is formed such that the jigs T engaging with the engagement portion 34 does not come into mutual contact with the cam ring 4 and the second pump body 20 in a state in which the contacting portion 32 is in contact with the cam ring 4. In other words, the seating member 31 may be formed to have an arbitrary shape as long as the seating member 31 is formed such that the jigs T engaging with the engagement portion 34 is in a non-mutual contact state with the cam ring 4 and the second pump body 20.

According to the second embodiment described above, the advantages described below are afforded.

In the vane pump 200, the spring 30 that has been compressed by the jigs T in the second pump body 20 via the seating member 31 is allowed to extend such that the seating member 31 comes into contact with the lever portion 6 of the cam ring 4. Thereafter, the jigs T is withdrawn to install the spring 30 in the second pump body 20. As described above, the jigs T are used to compress the spring 30 via the seating member 31, and the jigs T are not caught between the spring 30 and the seating surfaces 6 a and 20 a. Thus, the jigs T can be withdrawn from the second pump body 20 with ease, and so, it is possible to install the spring 30 in the second pump body 20 with ease. Therefore, the assemblability of the vane pump 200 is improved.

Configurations, operations, and effects of the embodiments according to the present invention will be collectively described below.

The vane pump 100 includes: the rotor 2 connected to the driving shaft 1; the plurality of vanes 3 provided so as to be capable of reciprocating in the radial direction with respect to the rotor 2; the cam ring 4 having the cam face 4 a on which the tip-ends of the vanes 3 slide with the rotation of the rotor 2, the cam ring 4 being provided so as to be capable of being made eccentric with respect to the rotor 2; the second pump body 20 configured to accommodate the cam ring 4; and the spring 30 interposed between the cam ring 4 and the second pump body 20 in a compressed state, the spring 30 being configured to bias the cam ring 4 in the direction in which the amount of eccentricity with respect to the rotor 2 is increased, wherein the cam ring 4 and the second pump body 20 have the seating surfaces 6 a and 20 a on which the spring 30 is seated and the grooves 6 b and 20 b formed in the seating surfaces 6 a and 20 a.

In addition, in the vane pump 100, the grooves 6 b and 20 b are the jig insertion grooves into which the jig T for compressing the spring 30 is inserted, the grooves 6 b and 20 b being formed at positions facing the spring 30.

In in addition, in the vane pump 100, the cam ring 4 has the main body portion 5 and the lever portion 6 provided with the seating surface 6 a, the main body portion 5 being formed with the cam face 4 a on which the tip-ends of the vanes 3 slide and the lever portion 6 being formed so as to extend from the main body portion 5 in the radial direction.

With such a configuration, the spring 30 that has been compressed by the jig T in the second pump body 20 is allowed to extend such that the jig T is inserted into the grooves 6 b and 20 b, and thereby, the spring 30 is seated on the seating surfaces 6 a and 20 a. Thereafter, the jig T is withdrawn from the grooves 6 b and 20 b to install the spring 30 in the second pump body 20. As described above, because the grooves 6 b and 20 b are formed in the seating surfaces 6 a and 20 a, the jig T is prevented from being caught between the spring 30 and the seating surfaces 6 a and 20 a, and so, the jig T is not subjected to the biasing force exerted by the spring 30. Thus, the jig T can be withdrawn from the second pump body 20 with ease. Thus, it is possible to install the spring 30 in the second pump body 20 with ease. Therefore, the assemblability of the vane pump 100 is improved.

In addition, the vane pump 200 includes: the rotor 2 connected to the driving shaft 1; the plurality of vanes 3 provided so as to be capable of reciprocating in the radial direction with respect to the rotor 2; the cam ring 4 having the cam face 4 a on which the tip-ends of the vanes 3 slide with the rotation of the rotor 2, the cam ring 4 being provided so as to be capable of being decentered with respect to the rotor 2; the second pump body 20 configured to accommodate the cam ring 4; the spring 30 interposed between the cam ring 4 and the second pump body 20 in a compressed state, the spring 30 being configured to bias the cam ring 4 in the direction in which the amount of eccentricity with respect to the rotor 2 is increased; and the seating member 31 on which the spring 30 is seated, the seating member 31 being provided between the spring 30 and the cam ring 4.

In addition, in the vane pump 200, the seating member 31 has the contacting portion 32, the seating portion 33 on which the spring 30 is seated, and the engagement portion 34, the contacting portion 32 being configured to come into contact with the cam ring 4 and the engagement portion 34 being configured to engage with the jig T for compressing the spring 30, and the jig T, which is engaged with the engagement portion 34, configured so as not to come into mutual contact with both of the cam ring 4 and the second pump body 20 in a state in which the contacting portion 32 is in contact with the cam ring 4.

With such a configuration, the spring 30 that has been compressed by the jig T in the second pump body 20 via the seating member 31 is allowed to extend such that the seating member 31 comes into contact with the cam ring 4. Thereafter, the jig T is withdrawn to install the spring 30 in the second pump body 20. As described above, the jig T are used to compress the spring 30 via the seating member 31, and the jig T is not caught between the spring 30 and the seating surface 6 a. As a result, the jig T can be withdrawn from the second pump body 20 with ease. Thus, it is possible to install the spring 30 in the second pump body 20 with ease. Therefore, the assemblability of the vane pump 200 is improved.

Embodiments of this invention were described above, but the above embodiments are merely examples of applications of this invention, and the technical scope of this invention is not limited to the specific constitutions of the above embodiments.

This application claims priority based on Japanese Patent Application No. 2016-182110 filed with the Japan Patent Office on Sep. 16, 2016, the entire contents of which are incorporated into this specification. 

1. A variable displacement vane pump comprising: a rotor connected to a driving shaft; a plurality of vanes provided so as to be capable of reciprocating in a radial direction with respect to the rotor; a cam ring having an inner circumferential surface on which tip-ends of the vanes slide with rotation of the rotor, the cam ring being provided so as to be made eccentric with respect to the rotor; an accommodating member configured to accommodate the cam ring; and a biasing member interposed between the cam ring and the accommodating member in a compressed state, the biasing member being configured to bias the cam ring in a direction in which an amount of eccentricity with respect to the rotor is increased; wherein at least one of the cam ring and the accommodating member has a seating surface on which the biasing member is seated and a groove formed in the seating surface.
 2. The variable displacement vane pump according to claim 1, wherein the groove is a jig insertion groove into which a jig for compressing the biasing member is inserted, the groove being formed at a position facing the biasing member.
 3. The variable displacement vane pump according to claim 1, wherein the cam ring has a main body portion and a lever portion provided with the seating surface, the main body portion being formed with the inner circumferential surface on which the tip-ends of the vanes slide, the lever portion being formed so as to extend from the main body portion in the radial direction.
 4. A variable displacement vane pump comprising: a rotor connected to a driving shaft; a plurality of vanes provided so as to be capable of reciprocating in a radial direction with respect to the rotor; a cam ring having an inner circumferential surface on which tip-ends of the vane slide with rotation of the rotor, the cam ring being provided so as to be capable of being decentered with respect to the rotor; an accommodating member configured to accommodate the cam ring; a biasing member interposed between the cam ring and the accommodating member in a compressed state, the biasing member being configured to bias the cam ring in a direction in which an amount of eccentricity with respect to the rotor is increased; and a seating member on which the biasing member is seated, the seating member being provided between the biasing member and the cam ring, wherein the seating member has a contacting portion, a seating portion on which the biasing member is seated, and an engagement portion, the contacting portion being configured to come into contact with the cam ring and the engagement portion being configured to engage with a jig for compressing the biasing member, and the jig, which is engaged with the engagement portion, as well as the cam ring and the accommodating member are configured so as not to come into mutual contact in a state in which the contacting portion is in contact with the cam ring.
 5. (canceled) 